At a closed White House meeting in April, President Obama told corporate insurance bosses that "we're all in this together" on implementing his signature health-care law. But some insurance companies seem to be more in than others. At least five Blue Cross and Blue Shield executives sat at the table of about a dozen chief executives with the president, according to people knowledgeable about the session, which was first reported by the New York Times. Just as significant is who wasn't there: chiefs of the country's biggest and third-biggest health insurers, UnitedHealth Group and Aetna.